(HBW150V is the old number; the new number is ZF15MIV). I had a lot of trouble with it in Florida in 2001 - the dealer rebuilt it twice but couldn't stop the seals from leaking - so I ended up putting a new one on. It started leaking last year, which they are notorious for. To repair would have been $1,000 IIRC because the shaft had pitted and would need to be replaced. The dealer said it showed signs of having overheated somewhere along the line. I have subsequently installed a SS cooler that taps into the seawater cooling lines. Besides keeping them cool, it is important to keep these in alignment and change the fluid regularly (every ~100 hours).

I have several friends who have had tranny problems and had to ship new units overseas. They are difficult to repair. As a result I bought two new units last winter: one to install and one for a spare. Expensive but good for peace of mind. I got a pretty good price from Marine Parts Express in Edgecomb, Maine (better price than anything I found on the net)

Good luck with it.